Straightforward stuff again this time. Last night I opened up a small passthrough on the upper cowl for the hinge pins, then laid out the rivet locations. Tonight I made some bracing blocks from wood, to support the aft end of the upper hinge half while drilling, then got the upper cowl in place and did the actual drilling.
I’m now trying to decide whether I want to go ahead and mark/cut the openings for the hinge pin covers, or if I should go ahead and rivet the horizontal hinges in place first. I’m kind of leaning towards the latter approach – I’ll likely want to do some sanding/shaping at the horizontal cowl joint, especially towards the front where the covers will be, and I can’t really finalize all that sanding/shaping until the hinges are permanently attached. The main reason for that is that things always fit differently with actual rivets instead of clecoes, and I don’t want to do any finish-fitting (eg setting the gap between cowl halves) with temporary fasteners in place.
On the other hand, just cutting the cover openings is pretty low impact, and would make installing/removing the pins a lot easier for the time being. The point at which I’ll want something resembling final fit is when I add the backer flange for the covers…but that can wait a little while. Maybe I’ll rough-cut the covers tomorrow and then switch gears to attaching the hinge halves.